采购提交与报销新建/提交事务显式使用10秒上限 [09-27-purchase-submit-tx-timeout]

负载下采购提交事务超过 Prisma 交互事务默认 5000ms（P2028）返回 500。
分段计时显示无单一瓶颈（总时长中位 843ms、最大 3506ms，编号锁等待
最多 535ms），是约 20 条顺序查询整体变慢贴近上限。报销新建/提交同结构。
三处改用项目既有的 { maxWait: 5000, timeout: 10000 }，事务内容不变；
新增采购与报销提交的事务选项回归断言。

Co-Authored-By: Claude Opus 5.5 <[email protected]>

server/tests/unit/routes/reimbursements.expense-standards.test.js

@@ -325,7 +325,7 @@ describe("reimbursements routes expense standard integration", () => {
 
   it.each([true, false])("avoids unused bound-invoice counts: per-item guard=%s", async invoiceGuardEnabled => {
     resolveEntityPrecheckMock.mockResolvedValue(buildPrecheck());
-    const { app, tx } = await buildApp({ invoiceGuardEnabled, reimbursementItems: [{
+    const { app, prisma, tx } = await buildApp({ invoiceGuardEnabled, reimbursementItems: [{
       id: "item-no-invoice", amount: "180.00",
       expense_type: { code: "office", category: "office", requires_invoice: invoiceGuardEnabled },
     }] });
@@ -336,6 +336,8 @@ describe("reimbursements routes expense standard integration", () => {
       expect(tx.reimbursementItem.findFirst).not.toHaveBeenCalled();
       expect(tx.reimbursementItem.aggregate).toHaveBeenCalledTimes(1);
       expect(tx.workflowHistory.create).toHaveBeenCalled();
+      // Prisma's 5s interactive-transaction default was exceeded under load (P2028 -> 500).
+      expect(prisma.$transaction).toHaveBeenCalledWith(expect.any(Function), { maxWait: 5000, timeout: 10000 });
     } finally { await app.close(); }
   });